1. Field of the Invention
The present invention relates to an alkylcyclohexanol alkylene oxide adduct, and a preparation process and uses of the same. More particularly, the invention relates to an alkylcyclohexanol alkylene oxide adduct which contains a trace amount or less of alkylphenol and alkylphenol alkylene oxide adduct, and a preparation process and uses of the same.
The alkylcyclohexanol alkylene oxide adduct of the invention is useful in the field of surfactants.
2. Description of the Related Art
Higher primary alcohol ethylene oxide adducts and nonylphenol alkylene oxide adduct have been conventionally known as nonionic surfactants. However, higher primary alcohol ethylene oxide adducts have a higher pour point, change to solid when the added molar numbers of ethylene oxide is increased, and become difficult to handle.
Alkylcyclohexanol alkylene oxide adducts also have excellent properties as a nonionic surfactant. Ethylene oxide adducts in particular have a lower pour point, can maintain a liquid state even in a relatively high addition mole number of ethylene oxide, can be handled with ease and thus have received attention as an excellent surfactant.
These alkylcyclohexanol alkylene oxide adducts are specifically useful for protein extraction from cell membrane in the biochemical field. When analyzing the extracted protein by ultraviolet or fluorescent spectrum, conventional alkylcyclohexanol alkylene oxide adduct contains a substanial amount of residual alkylphenol and alkylphenol alkylene oxide adduct and thus the ultraviolet or fluorescent spectrum of these compounds overlaps the spectrum of the extracted protein. As a result, it has a problem of impairing analysis accuracy, and the development of alkylcyclohexanol alkylene oxide adduct containing a less amount of residual alkylphenol and alkylphenol alkylene oxide adduct has been strongly desired.
As to the process for preparing alkylcyclohexanol ethylene oxide adducts and other alkylcyclohexanol alkylene oxide adducts having a higher alkyl group on a side chain of a cyclohexane ring, several processes have been known as shown below.
For example, German Laid-Open Patent 4417947 has disclosed a process for obtaining alkylcyclohexanol by hydrogenation of alkylphenol and successively reacting with ethylene oxide in the presence of a basic catalyst to prepare alkylcyclohexanol ethylene oxide adducts. However, the process leads to a relatively broad addition distribution of ethylene oxide, increases proportion of high molar adduct, and thus results in a solid reaction product which is unfavorable because of difficulty in handling as a surfactant. Further, the reaction of alkylcyclohexanol and other secondary alcohols with ethylene oxide in the presence of a basic catalyst has been generally known to have a very low reaction rate. For example, it has been described in H. Horiguchi (xe2x80x9cNew Surfactantsxe2x80x9d, page 626, published by Sankyo Shuppan Co. (1975) that ethylene oxide generally reacts very quickly with primary alcohol whereas slowly with secondary alcohol in the presence of a basic catalyst. Consequently, in the preparation of an alkylcyclohexanol ethylene oxide adduct by reaction of alkylcyclohexanol with ethylene oxide in the presence of a basic catalyst, a small amount of alkylcyclohexanol ethylene oxide adduct (primary alcohol) formed in the initial stage of the reaction preferentially reacts with ethylene oxide. As a result, unreacted alkylcyclohexanol remains in an extremely large quantity.
H. Stache et al. have obtained one molar ethylene oxide adduct of isooctylcyclohexanol by hydrogenation of one molar ethylene oxide adduct of isooctylphenol and have successively reacted the product with ethylene oxide to obtain isooctylcyclohexanol ethylene oxide adduct (Tr.-Mezhdunar. Kongr. Poverkhn.-Akt Veshchestvam 7th, Vol. 1(1977), 378-391). However, as to the hydrogenation reaction of one molar ethylene oxide adduct of isooctylphenol, no description can be found at all on the species of the catalyst used and the reaction conditions carried out. Further, no specific purification has been carried out after the hydrogenation reaction. Quite no description has been found on the amount of isooctylphenol ethylene oxide adduct remaining in the isooctylcyclohexanol ethylene oxide adduct thus obtained.
Further, German Patent No. 626965 has also obtained alkylcyclohexanol alkylene oxide adduct by the same process as that of H. Stache et al. The process also did not carry out specific purification of hydrogenation product. No description is found at all on the amount of alkylphenol alkylene oxide adduct remaining in the resulting alkylcyclohexanol alkylene oxide adduct.
Further, George E. Tillar et al. have obtained octylcyclohexanol ethylene oxide adduct by hydrogenation of octylphenol ethylene oxide adduct (Trade Mark: Triton X-100) in an ethanol solvent in the presence of a rhodium carbon catalyst (Analytical Biochemistry 141, 262-266 (1984)). The cited example has suggested that such a process remains 600 ppm of octylphenol ethylene oxide adduct even though the reaction time of hydrogenation is extended.
As mentioned above, several suggestions have been found on the preparation process of alkylcyclohexanol alkylene oxide adducts. However, in the present state of the art, almost no information has been obtained on the preparation process of alkylcyclohexanol alkylene oxide adducts which contain a reduced amount of residual alkylphenol and alkylphenol alkylene oxide adduct, have higher purity and narrow addition distribution of alkylene oxide.
Therefore, the object of the invention is to provide a high purity alkylcyclohexanol alkylene oxide adduct which has a narrow addition distribution of alkylene oxide and contains a trace amount or less of alkylphenol and alkylphenol alkylene oxide adduct, a simple and efficient preparation process of alkylcyclohexanol alkylene oxide adduct, and uses of the same.
As a result of an intensive investigation in order to solve the above subjects, the present inventors have found a process for efficiently preparing an alkylcyclohexanol alkylene oxide adduct which has a narrow addition distribution of alkylene oxide, contains a trace amount or less of impurities including alkylphenol and alkylphenol alkylene oxide adduct, and is represented by the formula (1). Thus the present invention has been completed. 
That is, the first aspect of the invention is an alkylcyclohexanol alkylene oxide adduct which contains 200 ppm or less of alkylphenol and alkylphenol alkylene oxide adduct and is represented by the formula (1): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more.
The second aspect of the invention is a preparation process of an alkylcyclohexanol alkylene oxide adduct which contains a trace amount or less of alkylphenol alkylene oxide adduct and is represented by the formula (1), comprising hydrogenating alkylphenol alkylene oxide adduct represented by the formula (2): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more, 1) in the absence of a solvent, 2) in the presence of a saturated hydrocarbon solvent, or 3) in the presence of water.
The third aspect of the invention is a preparation process of a high purity alkylcyclohexanol alkylene oxide adduct which has a narrow addition distribution of alkylene oxide and is represented by the formula (1), comprising adding one mole of alkylene oxide having 2 to 4 carbon atoms to alkylphenol represented by the formula (4): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, thereafter hydrogenating and distillating to obtain alkylene oxide one molar adduct of alkylcyclohexanol which contains a trace amount of alkylphenol and alkylphenol alkylene oxide adduct, and successively adding alkylene oxide in the presence of a basic catalyst.
The fourth aspect of the invention is a preparation process of a high purity alkylcyclohexanol alkylene oxide adduct which has a narrow addition distribution of alkylene oxide and is represented by the formula (1), comprising hydrogenating alkylphenol represented by the formula (4), thereafter distillating to obtain alkylcyclohexanol which contains a trace amount of alkylphenol, and successively adding alkylene oxide having 2 to 4 carbon atoms in the presence of an acid catalyst, and further distillating the reaction product.
Alkylcyclohexanol alkylene oxide adduct of the present invention is represented by the formula (1): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more, and corresponds to the nuclear hydrogenation product of alkylphenol alkylene oxide adduct represented by the formula (2): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more.
On the formula (2) of alkylphenol alkylene oxide adduct in the invention, R1 is an alkyl group having 6 to 20 carbon atoms. No particular restriction is imposed upon the structure of R1. R1 can be a straight chain structure or branched structure or any isomeric structure of an alkyl group. The attached position of R1 can be any of the 2, 3 or 4 position to the alkoxylate group (xe2x80x94O(CH2CHR2O)n H group) on the benzene ring. Further, R2in the oxyalkylene units (xe2x80x94CH2CHR2Oxe2x80x94units) is a hydrogen atom, methyl or ethyl group. Oxyalkylene units are specifically oxyethylene units (xe2x80x94CH2CH2Oxe2x80x94units), oxypropylene units (xe2x80x94CH2CH(CH3)Oxe2x80x94 units) or oxybutylene units (xe2x80x94CH2CH(CH2CH3)Oxe2x80x94 units). n is an integer of 1 or more. When n is 2 or more, recurring units can have only one of the oxyethylene units, oxypropylene units or oxybutylene units, or can have 2 or more oxyalkylene units. When 2 or more species of oxyalkylene units are present, the units can be in a random addition or block addition. No particular limitation is imposed upon the range of n. However, n is usually in the range of 1 to 50. When n is 1, the compound can be specifically one molar adduct of alkylene oxide or one molar alkylene oxide adduct.
Alkylphenol alkylene oxide adduct represented by the formula (2) includes structural isomers of R1 and an alkoxylate group, and compounds which differ in the species and numbers and numbers of the oxyalkylene group. These compounds can be used singly and are usually used as a mixture. Further, these compounds can be a mixture of two species or more alkylphenol alkylene oxide adducts which are represented by the formula (2) and differ in the carbon numbers of the alkyl group R1.
Specific alkylphenol alkylene oxide adducts represented by the formula (2) include, for example, ethylene oxide adduct of hexylphenol, heptylphenol, octylphenol, nonylphenol, decylphenol, undecylphenol, tridecylphenol, tetradecylphenol, pentadecylphenol, hexadecylphenol, heptadecylphenol, octadecylphenol, nonadecylphenol, eicosylphenol and other alkylphenols; for example, propylene oxide adduct of hexylphenol, heptylphenol, octyphenol, nonylphenol, decylphenol, undecylphenol, tridecylphenol, tetradecylphenol, pentadecylphenol, hexadecylphenol, heptadecylphenol, octadecylphenol, nonadecylphenol eicosylphenol and other alkylphenols; for example, butyleneoxide adduct of hexylphenol, heptylphenol, octylphenol, nonylphenol, decylphenol, undecylphenol, tridecylphenol, tetradecylphenol, pentadecylphenol, hexadecylphenol, heptadecylphenol, octadecylphenol, nonadecylphenol, eicosylphenol and other alkylphenols; for example, octylphenol(ethylene oxide/propylene oxide) random copolymer, octylphenol(ethylene oxide/butylene oxide) random copolymer, octylphenol(propylene oxide/butylene oxide) random copolymer, nonylphenol(ethylene oxide/propylene oxide) random copolymer nonylphenol(ethylene oxide/butylene oxide) random copolymer, nonylphenol(propylene oxide/butylene oxide) random copolymer and other alkylphenol alkylene oxide random copolymers; and for example, octylphenol(ethylene oxide/propylene oxide) block copolymer, octylphenol(ethylene oxide/butylene oxide) block copolymer, octylphenol(propylene oxide/butylene oxide) block copolymer, nonylphenol(ethylene oxide/propylene oxide) block copolymer, nonylphenol(ethylene oxide/butylene oxide) block copolymer, nonylphenol(propylene oxide/butylene oxide) block copolymer and other alkylphenol alkylene oxide block copolymers.
Further, alkylcyclohexanol of the invention is represented by the formula (3): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, and corresponds to the hydrogenation product of alkylphenol represented by the formula (4): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms.
On the formula (4) of alkylphenol in the invention, R1 is an alkyl group having 6 to 20 carbon atoms. No particular restriction is imposed upon the structure of R1. R1 can be a straight chain structure or branched structure or any isomeric structure of an alkyl group. The attached position of R1 can be any of the 2, 3 or 4 position to the hydroxyl group (xe2x80x94OH group) on the benzene ring. Alkylphenol represented by the formula (4) has structural isomers of R1 and hydroxyl group. These isomers can be usually used as a mixture and can also be used singly. Further, a mixture of alkylphenols which differ in the number of carbon atom on the alkyl group R1 can also be used.
Representative alkylphenols represented by the formula (4) include, for example, hexylphenol, heptylphenol, octylphenol nonylphenol, decylphenol, undecylphenol, tridecylphenol, tetradecylphenol, pentadecylphenol, hexadecylphenol, heptadecyplphenol octadecylphenol, nonadecylphenol, eicosylphenol, and other alkylphenols.
Further, alkylene oxides having 2 to 4 carbon atoms in the invention specifically include ethylene oxide, propylene oxide and butylene oxide. These alkylene oxides can be used singly or as a mixture. When two or more alkylene oxides are used as a mixture both random addition and block addition can be carried out.
The alkylcyclohexanol alkylene oxide adduct which has a narrow addition distribution of alkylene oxide, and contains a trace amount or less of alkylphenol and alkylphenol alkylene oxide adduct can be prepared by the preparation processes (A) to (E) below.
The alkylcyclohexanol alkylene oxide adduct of the invention represented by the formula (1); 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more, is prepared by reacting alkylphenol alkylene oxide adduct represented by the formula (2): 
wherein R1, R2 and n are the same as above, with hydrogen under hydrogen gauge pressure exceeding 2.0 MPa, at temperature of 80 to 150xc2x0 C., in the absence of a solvent, and in the presence of a supported catalyst of ruthenium or rhodium.
The process is characterized by reacting alkylphenol alkylene oxide adduct with hydrogen in the absence of a solvent. The reaction in the absence of a solvent can provide the desired alkylcyclohexanol alkylene oxide adduct in a high degree of conversion merely by removing the catalyst without solvent recovery procedure.
The process reacts alkylphenol alkylene oxide adduct with hydrogen in the presence of a supported catalyst of ruthenium or rhodium. Representative supported catalysts of ruthenium or rhodium include, for example, ruthenium carbon, rhodium carbon and other carbon supported catalysts of these metals; ruthenium alumina, rhodium alumina and other alumina supported catalysts of these metals; and ruthenium titania and other titania supported catalyst of these metals. No particular limitation is imposed upon the supported amount of these metals. The amount is usually in the range of 0.01 to 20% by weight. These catalysts can be crushed or powdered or molded into pellet or sphere. In these catalysts, ruthenium or rhodium catalyst supported on carbon or alumina is preferred in view of excellent activity and selectivity.
In the process, the reaction is carried out at temperature of 80 to 150xc2x0 C. under hydrogen gauge pressure exceeding 2.0 MPa in order to prepare alkylcyclohexanol alkylene oxide adduct in good efficiency and high selectivity. When the hydrogen gauge pressure is 2.0 MPa or less, the hydrogenation reaction is very slow. On the other hand, the gauge pressure exceeding 15 Mpa requires very high pressure resistance to the reactor and thus the upper limit of the hydrogen pressure is preferably gauge pressure of 15 Mpa. Further, the reaction temperature less than 80xc2x0 C. leads to very low reaction rate of hydrogenation reaction. On the other hand, the reaction temperature exceeding 150xc2x0 C. tends to cause side reactions such as cleavage of ether bonds due to a hydrogenation decomposition reaction, and unfavorably lowers selectivity of alkylcyclohexanol alkylene oxide adduct. More preferred hydrogen pressure and reaction temperature differ depending upon species and amount of the catalyst used and numbers of oxyalkylene units in the alkylcyclohexanol alkylene oxide adduct and are suitably selected in the specified ranges of hydrogen pressure and reaction temperature.
No particular restriction is imposed upon the procedures for carrying out the reaction. Batch procedure, semi-batch procedure and continuous procedure can be carried out. No particular limitation is put upon the amount of the catalyst in the batch and semi-batch procedures. The amount of the catalyst is usually in the range of 0.5 to 50% by weight for the alkylphenol alkylene oxide adduct used as a raw material. The reaction time is usually in the range of 0.5 to 50 hours. When the reaction is carried out by the continuous procedure, reaction conditions differ depending upon the species of the catalyst and other factors. LHSV is usually in the range of 0.01 to 50 hrxe2x88x921.
Alkylcyclohexanol alkylene oxide adduct of the invention represented by the formula (1): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more, can also be prepared by reacting alkylphenol alkylene oxide adduct represented by the formula (2): 
wherein R1, R2 and n are the same as above, with hydrogen in the presence of water by use of a supported catalyst of ruthenium, rhodium, palladium or platinum.
Alkylcyclohexanol alkylene oxide adduct of the invention is characterized by reacting alkylphenol alkylene oxide adduct with hydrogen in the presence of water by use of a supported catalyst of ruthenium, rhodium, palladium or platinum.
The catalyst used for the process can be a supported catalyst of ruthenium, rhodium, palladium or platinum. Representative supported catalysts of ruthenium, rhodium, palladium and platinum include, for example, ruthenium carbon, rhodium carbon, palladium carbon, platinum carbon and other carbon supported catalysts of these metals; ruthenium alumina, rhodium alumina and other alumina supported catalysts of these metals; palladium silica alumina, platinum silica alumina and other silica alumina supported catalysts of these metals; palladium silica magnesia, and other silica magnesia supported catalysts of these metals; palladium zeolite and other zeolite supported catalysts of these metals; palladium barium sulfate and other barium sulfate supported catalysts of these metals; and ruthenium titania and other titania supported catalysts of these metals. Further, catalysts supported by two species or more metals at the same time in an arbitrary proportion can also be used. Exemplary catalysts of such type include, for example, ruthenium-rhodium carbon, palladium-platinum carbon and other carbon supported catalysts of these metals; and ruthenium-rhodium alumina, palladium-platinum alumina and other alumina supported catalysts of these metals. These supported catalysts can be used singly or as a mixture of any proportion. No particular limitation is put upon the supported amount of these metals. The supported amount is usually in the range of 0.01 to 20% by weight. These catalysts can be powdered, crushed or molded into pellet or globe. Further, water containing catalyst which can be commonly obtained with ease in the market can preferably be used.
In these supported catalysts, carbon or alumina supported catalyst of ruthenium is preferably used in view of excellent activity and selectivity.
The process carries out reaction in the presence of water. The water charged to the reaction system can be previously dissolved, dispersed or impregnated into the raw material such as alkylphenol alkylene oxide adduct, catalyst or solvent, when used, or can also be independently charged to the reaction system.
No particular limitation is imposed upon the amount of water. The amount of water is usually in the range of 1 to 50% by weight, preferably 1 to 40% by weight for the amount of alkylphenol alkylene oxide adduct used for the raw material.
The process can be carried out in the presence or absence of a solvent. Any type of a solvent can be used so long as the solvent, when used, can dissolve or disperse the raw material alkylphenol alkylene oxide adduct and the solvent itself cannot be hydrogenated.
Exemplary solvents which can be used include, for example, methanol, ethanol, isopropyl alcohol, t-butylalcohol, cyclohexanol, 4-methylcyclohexanol, 1,2-ethanediol, glycerol and ether alcohol compounds; pentane, hexane, heptane, 2-methylpentane and other aliphatic hydrocarbon compounds; cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, bicyclohexyl, decalin and other aliphatic cyclic hydrocarbon compounds; dichloromethane, carbon tetrachloride, butyl chloride, propyl bromide, chlorocyclohexanol and other halogenated hydrocarbon compounds; diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran 1,2-dimethoxyethane and other ether compounds; acetone, methyl ethyl ketone, diisobutyl ketone, acetylacetone and other ketone compounds; methyl formate, ethyl acetate, ethylene carbonate and other ester compounds; and nitromethane, acetonitrile and other nitrogen compounds. These solvents can be used singly or as a mixture.
Specifically, when alcohol compounds such as ethanol are used as a solvent, the hydrogenating reaction in the absence of water has a very low rate of reaction and leaves a large amount of unreacted alkylphenol alkylene oxide adduct. However, it is surprising that, when the hydrogenation reaction is carried out in alcohol compounds in the presence of water, the reaction rate is extremely accelerated and almost no unreacted alkylphenol alkylene oxide adduct remains after the hydrogenation reaction.
The reaction is usually carried out at reaction temperature of 30 to 200xc2x0 C., preferably 50 to 150xc2x0 C. under the hydrogen gauge pressure of 0 to 20 MPa, preferably 0.5 to 15 MPa. More preferred hydrogen pressure and reaction temperature differ depending upon the species and amount of the catalyst used and the numbers of oxyalkylene units in the alkylphenol alkylene oxide adduct, and are suitably selected.
No particular restriction is put upon the procedures for carrying out the reaction. Batch procedure, semi-batch procedure and continuous procedure can be carried out. No particular limitation is imposed upon the amount of the catalyst in the batch and semi-batch procedures. The amount of the catalyst is usually in the range of 0.5 to 50% by weight for the alkylphenol alkylene oxide adduct used as a raw material. The reaction time is usually in the range of 0.5 to 50 hours. When the reaction is carried out by the continuous procedure, reaction conditions differ depending upon the species of the catalyst and other factors. LHSV is usually in the range of 0.01 to 50 hrxe2x88x921.
Alkylcyclohexanol alkylene oxide adduct of the invention represented by the formula (1): 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more, can also be prepared by reacting alkylphenol alkylene oxide adduct represented by the formula (2): 
wherein R1, R2 and n are the same as above, with hydrogen in the saturated hydrocarbon solvent in the presence of a hydrogenation catalyst.
The hydrogenation catalyst used in the process can be the same supported catalyst of ruthenium, rhodium, palladium or platinum which can be used in the preparation process (B), as mentioned above. These supported catalysts can be used singly or as a mixture of any proportion. No particular limitation is put upon the supported amount of these metals. The supported amount is usually in the range of 0.01 to 20% by weight. These catalysts can be powdered, crushed or molded into pellet or globe. Further, water containing catalyst which can be commonly obtained with ease in the market can preferably be used.
In these catalysts, the ruthenium catalyst supported on carbon or alumina is preferred in view of excellent catalytic activity and selectivity.
The process is characterized by carrying out in the presence of a saturated hydrocarbon solvent. No particular restriction is imposed upon the structure of the saturated hydrocarbon solvent used. The solvents having straight chain structure, branched structure and cyclic structure can be used. Any type of solvent can be used so long as the solvent can dissolve or disperse the raw material alkylphenol alkylene oxide adduct of the formula (2) and the product alkylcyclohexanol alkylene oxide adduct of the formula (1) and the solvent itself cannot be hydrogenated. Representative solvents which can be used in the process include, for example, n-pentane, n-hexane, n-heptane, n-octane, n-dodecane and other straight chain saturated hydrocarbons; 2-methylbutane, 2-methylpentane, 2-methylhexane, 2-methylheptane, 3-methylpentane, 3- ethylpentane, 3-methylhexane, 3-ethylhexane, 3-methylheptane, 2,2-dimethylpropane, 2,2-dimethylbutane, 2,2-dimethylhexane, 2,3-dimethylbutane, 3-methyl-3-ethylpentane, 2,2,3-trimethylbutane and other branched saturated hydrocarbons; and cyclopentane, cyclohexane, decalin, methylcyclopentane, methylcyclohexane, p-menthane and other cyclic saturated hydrocarbons. These solvents can be used singly or as a mixture. In these saturated hydrocarbon solvents, cyclic saturated hydrocarbon is particularly preferred in view of reactivity and selectivity. No particular limitation is imposed upon the amount of the saturated hydrocarbon solvent. The amount of the solvent used is commonly in the range of providing a concentration of 5 to 80% by weight, preferably 20 to 60% by weight for the raw material alkylphenol alkylene oxide adduct.
In proceeding the reaction, the presence of water is preferred because reaction rate is enhanced without giving an adverse effect on the selectivity of the reaction. Water, when used, can be previously dissolved, dispersed or impregnated in the raw material alkylphenol alkylene oxide adduct of the formula (2), catalyst or solvent, or can be independently charged to the reaction system. No particular limitation is imposed on the amount of water. The amount of water is usually in the range of 0.1 to 50% by weight, preferably 1 to 40% by weight for the raw material alkylphenol alkylene oxide adduct of the formula (2).
Hydrogen pressure and reaction temperature of the process are the same as those used in the preparation process (B). More preferred hydrogen pressure and reaction temperature differ depending upon the species and amount of the catalyst used and numbers of oxyethylene units in the alkylphenol alkylene oxide adduct of the formula (2), and thus these reaction conditions are arbitrarily selected.
No particular restriction is imposed upon the procedure of the reaction. Batch procedure, semi-batch procedure and continuous procedure can be carried out. When the reaction is carried out by batch or semi-batch procedures, no particular limitation is imposed upon the amount of catalyst. The amount is usually in the range of 0.5 to 50% by weight for the raw material alkylphenol alkylene oxide adduct of the formula (2). The reaction time is commonly in the range of 0.5 to 50 hours. When the reaction is carried out by continuous procedures, the reaction conditions differ depending upon the species of the catalyst. LHSV is usually in the range of 0.01 to 50 hrxe2x88x921.
Preparation processes (A), (B) and (C) can provide alkylcyclohexanol alkylene oxide adduct containing 200 ppm or less of unreacted alkylphenol alkylene oxide adduct.
Alkylcyclohexanol alkylene oxide adduct having further decreased content of alkylphenol alkylene oxide adduct and alkylphenol can be obtained by below described preparation processes (D) and (E) which have an added step of distillation.
In the process, the preparation of high purity alkylcyclohexanol alkylene oxide adduct represented by the formula (1); 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more, is characterized by consisting of below described four steps;
1) the first alkylene oxide addition step for reacting 1 mole of alkylphenol represented formula (4); 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, with 0.9 to 1.2 moles of alkylene oxide having 2 to 4 carbon atoms in the presence of a basic catalyst to obtain a formed product primarily consisting of one molar alkylene oxide adduct of alkylphenol,
2) the hydrogenation step for reacting the formed product of the first alkylene oxide addition step with hydrogen in the presence of a hydrogenation catalyst to obtain a formed product primarily consisting of one molar alkylene oxide adduct of alkylcyclohexanol,
3) the distillation step for distillating the formed product of the hydrogenation step to obtain a fraction primarily consisting of one molar alkylene oxide adduct of alkylcyclohexanol and containing 10 ppm by weight or less in the sum of alkylphenol and alkylphenol alkylene oxide adduct, and
4) the second alkylene oxide addition step for reacting the fraction obtained in the distillation step and primarily consisting of one molar alkylene oxide adduct of alkylcyclohexanol with alkylene oxide in the presence of a basic catalyst.
The alkylene oxide having 2 to 4 carbon atoms which can be used in the first and second alkylene oxide addition steps includes, for example, ethylene oxide, propylene oxide and butylene oxide. Alkylene oxide can be used singly or as a mixture. When alkylene oxide is used as a mixture, both random and block addition can be carried out.
Exemplary, basic catalysts which are used in the first alkylene oxide addition step include, for example, sodium hydroxide, potassium hydroxide, cesium hydroxide and other alkali metal hydroxides; sodium ethoxide, lithium ethoxide, potassium phenoxide and other alkali metal alkoxides or phenoxides; calcium hydroxide, barium hydroxide, strontium hydroxide and other alkali earth metal hydroxides; calcium methoxide, calcium phenoxide and other alkali earth metal alkoxides or phenoxides; magnessium oxide, barium oxide and other alkali earth metal oxides. In these basic catalysts, alkali metal hydroxides are preferably used. Amount of the catalyst differs depending upon the species of the catalyst and reaction temperature and reaction temperature and is usually in the range of 10 to 5,000 ppm by weight for the raw material alkylphenol.
The basic catalyst which is soluble in the reaction product can be converted to a soluble salt of organic acid by neutralizing with an organic acid after the reaction, or can be neutralized with a mineral acid such as sulfuric acid and the precipitated mineral acid salt is removed by filtration. Alternatively, the reaction mass can be used as intact to the next hydrogenation step without neutralization. Further, the catalyst which is insoluble in the reaction product can be usually removed by filtration and successively the next hydrogenation step is carried out.
The first alkylene oxide addition step reacts 1 mole of alkylphenol with 0.9 to 1.2 moles of alkylene oxide having 2 to 4 carbon atoms and primarily prepares one molar alkylene oxide adduct of alkylphenol. When addition amount of alkylene oxide is less than the above range, an increased amount of unreacted alkylphenol remains after the reaction. On the other hand, the addition amount of alkylene oxide more than the above range increases formation of compounds having two moles or more alkylene oxide addition to alkylphenol.
The object of the first alkylene oxide addition step is to prepare one molar ethylene oxide adduct of alkylphenol which can maintain primary alcohol even after the hydrogenation step and can be readily purified by distillation. Thus, it is unfavorable to leave a substantial amount of alkylphenol which converts to secondary alcohol after the hydrogenation step, or to form a substantial amount of two or more molar alkylene oxide adduct of alkylphenol which has a high boiling point and is difficult to purify by distillation.
The reaction temperature in the first alkylene oxide addition step is usually in the range of 60 to 230xc2x0 C., preferably 120 to 200xc2x0 C. The reaction time is usually in the range of 0.1 to 30 hours, preferably 0.3 to 20 hours. The gauge pressure in the reaction is usually in the range of 0 to 2 MPa, preferably 0.1 to 0.7 MPa. Any of the batch procedure, semi-batch procedure and continuous procedure can be carried out.
The hydrogenation catalysts which are used in the hydrogenation step of the process can be any species of the catalyst so long as the catalysts is capable of hydrogenating the aromatic ring of the formed product which is obtained in the first alkylene oxide addition step and primarily consisting of one molar alkylene oxide adduct of alkylphenol, with hydrogen to obtain a cyclohexane ring. Representative of such catalysts include, for example, supported catalysts of ruthenium, rhodium, palladium and platinum, complex catalysts of these metals, and Raney nickel and Raney cobalt. Specific supported catalysts of ruthenium, rhodium, palladium, and platinum include, for example, ruthenium carbon, rhodium carbon, palladium carbon, platinum carbon and other carbon supported catalysts of metals, ruthenium alumina, rhodium alumina and other alumina supported catalysts of metals; palladium silica alumina and other silica alumina supported catalysts of metals; palladium zeolite and other zeolite supported catalysts of metals; palladium barium sulfate and other barium sulfate supported catalysts of metals; and ruthenium titania and other titania supported catalysts of metals. No particular limitation is imposed upon the supported amount of metals. The amount is usually in the range of 0.01 to 20% by weight. These catalysts can be powdered, crushed or molded into pellet or sphere.
Representative complex catalysts of ruthenium, rhodium, palladium and platinum include, for example, ruthenium chloride, palladium bromide and other halogenides of metal; palladium acetate, rhodium propionate and other carboxylates of metal; palladium acetylacetonate, ruthenium acetylacetonate and other acetylacetonate complexes of metal; and dichlorotris-(triphenylphosphine) ruthenium, chlorotris(triphenylphosphine) rhodium, dichlorobis(triphenylphosphine) palladium, dichlorobis(triphenylphosphine) platinum and other phosphine complex of these metals. These complex catalysts can be used singly or as a mixture.
In these catalysts, carbon or alumina supported catalysts of ruthenium or rhodium and Raney nickel are preferred in view of excellent catalytic activity and selectivity.
In the hydrogenation step of the process, hydrogen pressure is usually in the range of gauge pressure of 0 to 20 MPa, preferably 0.5 to 15 MPa in the gauge pressure. Reaction temperature is usually in the range of 30 to 200xc2x0 C., preferably 50 to 150xc2x0 C.
The reaction can be carried out in the presence or absence of a solvent. Any solvent can be used for the process so long as the solvent can dissolve or disperse the raw material, one molar alkylene oxide adduct of alkylphenol and one molar alkylene oxide adduct of corresponding alkylcyclohexanol which is a formed product and the solvent itself does not react with hydrogen in the above reaction conditions. The solvents used in the preparation process (B) can be used as intact for the process.
In these solvents, aliphatic hydrocarbon compounds and aliphatic cyclic hydrocarbon compounds are preferably used, and aliphatic cyclic hydrocarbon compounds are preferred in particular. No particular limitation is imposed upon the amount of solvents. The amount is usually in the range of providing a concentration of usually 5 to 80% by weight, preferably 20 to 60% by weight for the raw material, one molar alkylene oxide adduct of alkylphenol.
When one molar alkylene oxide adduct of alkylphenol is reacted with hydrogen in the presence of a solvent, the reaction rate is sometimes low and preferable yield cannot be obtained in the reaction. Particularly, ethanol and other alcohol solvents require a long reaction time and lead to inferior productivity. In such a case, the reaction can be preferably carried out in the presence of water because the reaction rate is preferably accelerated without giving an adverse effect on the selectivity. Water, when used, can be previously dissolved, dispersed or impregnated into the raw material, one molar alkylene oxide adduct of alkylphenol, catalyst or solvent, or can be independently charged to the reaction system. No particular limitation is imposed upon the amount of water. The amount is usually in the range of 0.1 to 50% by weight, preferably 1 to 40% by weight for the raw material, one molar alkylene oxide adduct of alkylphenol.
No particular restriction is put upon the procedures for carrying out the reaction. Any of batch procedure, semi-batch procedure and continuous procedure can be carried out. No particular limitation is imposed upon the amount of catalyst when the reaction is carried out by batch or semi-batch procedure. The amount of catalyst is usually in the range of 0.5 to 50% by weight for the raw material one molar alkylene oxide adduct of alkylphenol. The reaction time is usually in the range of 0.5 to 50 hours. When the reaction is carried out by the continuous procedure, reaction conditions differ depending upon the species of the catalyst used and is usually in the range of 0.01 to 50 hrxe2x88x921 in LHSV. After finishing the reaction, the formed product which is primarily consisting of one molar alkylene oxide adduct of alkylcyclohexanol can be obtained by removing the catalyst with a common solid-liquid separation method. When the solvent is used, the formed product desired can be obtained by separating the catalyst from the reaction mass and distilling off the solvent from the filtrate.
In the process, the formed product obtained in the hydrogenation step is distilled to provide a fraction consisting primary of one molar alkylene oxide adduct of alkylcyclohexanol and containing 10 ppm by weight or less in the sum of unreacted alkylphenol and alkylphenol alkylene oxide adduct. The term alkylphenol alkylene oxide adduct refers to any compounds obtained by adding one molar or more alkylene oxide to alkylphenol. The object of the distillation step is to fractionate alkylphenol and alkylphenol alkylene oxide adduct and to obtain a fraction which is almost free from these compounds and primarily consists of one molar alkylene oxide adduct of alkylcyclohexanol. The fraction can contain a small amount of alkylcyclohexanol and two molar or more alkylene oxide adduct of alkylcyclohexanol. The distillation can be carried out by batch or continuous procedures.
In the second alkylene oxide addition step, a fraction of distillation step consisting primarily of one molar alkylene oxide adduct of alkylcyclohexanol is reacted with alkylene oxide having 2 to 4 carbon atoms in the presence of a basic catalyst to obtain high purity alkylene oxide adduct of alkylcyclohexanol.
The basic catalysts used in the step are the same as used in the first alkylene oxide addition step. Alkali metal hydroxide is preferred in these basic catalysts. The amount of the catalyst is usually in the range of 10 to 5,000 ppm by weight for the raw material fraction consisting primarily of one molar alkylene oxide adduct of alkylcyclohexanol. No particular restriction is imposed upon the addition numbers of alkylene oxide. The numbers are suitably selected depending upon uses of the alkylene oxide adduct obtained. Reaction temperature and reaction pressure are usually the same as those in the first alkylene oxide addition step. Reaction time differs depending upon the amount of alkylene oxide to be added and is usually in the range of 0.5 to 50 hours.
The alkylcyclohexanol alkylene oxide adduct obtained in the preparation processes (D) and represented by the formula (1) has a 10 ppm or less content of alkylphenol and alkylphenol alkylene oxide adduct, has a narrow addition distribution, and can be used as a material of surface active agents.
The process for preparing high purity alkylcyclohexanol alkylene oxide adduct represented by the formula (1); is characterized by consisting of below described four steps; 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, R2 is a hydrogen atom, methyl or ethyl group, and n is an integer of 1 or more,
1) the hydrogenation step for reacting alkylphenol represented by the formula (4); 
wherein R1 is an alkyl group having 6 to 20 carbon atoms, with hydrogen in the presence of a hydrogenation catalysts to obtain a formed product primarily consisting of corresponding alkylcyclohexanol represented by the formula (3); 
wherein R1 is the same as above,
2) the first distillation step for distillating the formed product obtained in the hydrogenation step to provide alkylphenol content of 10 ppm by weight or less in the fraction primarily consisting of alkylcyclohexanol,
3) an alkylene oxide addition step for reacting one mole of alkylcyclohexanol obtained in the first distillation step with 1 to 5 moles of alkylene oxide having 2 to 4 carbon atoms in the presence of an acid catalyst to prepare alkylcyclohexanol alkylene oxide adduct, and
4) the second distillation step for separating unreacted alkylcyclohexanol and low boiling-point byproduct of the reaction from alkylcyclohexanol alkylene oxide adduct obtained in the alkylene oxide addition step.
The hydrogenation step of the process can use the same catalyst as used in the preparation process (D).
Hydrogen pressure in the hydrogenation step of the process is usually in the range of gauge pressure 0 to 20 MPa, preferably 0.5 to 15 MPa. Reaction temperature is usually in the range of 30 to 200xc2x0 C., preferably 50 to 150xc2x0 C.
The reaction can be carried out in the presence or absence of a solvent. Any solvent can be used for the process so long as the solvent can dissolve or disperse the raw material alkylphenol and corresponding alkylcyclohexanol which is a formed product and the solvent itself does not react with hydrogen in the above reaction conditions. The solvents used in the preparation process (B) can be used as intact for the process.
In these solvents, aliphatic hydrocarbon compounds and aliphatic cyclic hydrocarbon compounds are preferably used, and aliphatic cyclic hydrocarbon compounds are preferred in particular. No particular limitation is imposed upon the amount of solvents. The amount is usually in the range of providing a concentration of usually 5 to 80% by weight, preferably 20 to 60% by weight for the raw material alkylphenol.
When alkylphenol is reacted with hydrogen in the presence of a solvent, the reaction rate is sometimes low and preferable yield cannot be obtained in the reaction. Particularly, ethanol and other alcohol solvents require a long reaction time and lead to inferior productivity. In such a case, the reaction can be preferably carried out in the presence of water because the reaction rate is preferably accelerated without giving an adverse effect on the selectivity. Water, when used, can be previously dissolved, dispersed or impregnated into the raw material alkylphenol of the formula (3), catalyst or solvent, or can be independently charged to the reaction system. No particular limitation is imposed upon the amount of water. The amount is usually in the range of 0.1 to 50% by weight, preferably 1 to 40% by weight for the raw material alkylphenol.
No particular restriction is imposed upon the reaction procedures in the hydrogenation step. Any of batch procedure, semi-batch procedure and continuous procedure can be carried out. When the reaction is carried out by batch or semi-batch procedure, no particular limitation is put upon the amount of the catalyst. The amount is usually in the range of 0.5 to 50% by weight for the raw material alkylphenol. The reaction time is usually in the range of 0.5 to 50 hours. When the reaction is carried out by the continuous procedure, the reaction conditions differ depending upon the species of the catalyst used and LHSV is usually in the range of 0.01 to 50 hrxe2x88x921. After finishing the reaction, the formed product which consists primarily of alkylcyclohexanol can be obtained by separating the catalyst with a usual solid-liquid separation method. When a solvent is used, the desired product can be obtained by distillating off the solvent after separating the catalyst from the reaction mixture.
In a formed product obtained in the hydrogenation step and composed primarily of alkylcyclohexanol, unreacted alkylphenol remains though in a trace amount. The residual alkylphenol influences the successive reaction and leads to quality reduction of the final product alkylcyclohexanol alkylene oxide adduct. Accordingly, the first distillation step below is carried out.
The first distillation step of the invention distillates the formed product in the hydrogenation step and reduces the content of alkylphenol to 10 ppm by weight or less in the fraction consisting of alkylcyclohexanol. The object of the distillation step is to obtain an alkylcyclohexanol fraction containing a trace amount or less of impurity by separating alkylphenol with distillation. Accordingly, a distillation apparatus equipped with a rectifying column and a reflux condenser can be used. The distillation can be carried out at atmospheric pressure or under reduced pressure.
Further, a high purity alkylcyclohexanol fraction containing a trace amount or less of alkylphenol can be obtained by carrying out the distillation step in the presence of a basic compound without using the rectification, column, reflux condenser and other high grade distillation equipment. The basic compounds which can be used in the distillation step are organic and inorganic compounds having basicity and include, for example, sodium hydroxide, potassium hydroxide, cesium hydroxide and other alkali metal hydroxides; sodium ethoxide, lithium ethoxide, potassium phenoxide and other alkali metal alkoxides and phenoxides; calcium hydroxide, barium hydroxide, strontium hydroxide and other alkali earth metal hydroxides; calcium methoxide, calcium phenoxide and other alkali earth metal alkoxides and phenoxides; magnesium oxide, barium oxide and other alkali earth metal oxides; and triethylamine, dimethylamine, aniline, morpholine, pyridine and other organic amino compounds. In these basic compounds, alkali metal hydroxides are preferably used due to low price and handling with ease. No particular limitation is imposed upon the amount of basic compounds. The amount is usually in the range of 1 to 1,000 moles per mole of the raw material alkylphenol contained in the formed product consisting primarily of alkylcyclohexanol.
Distillation can be carried out by both batch and continuous procedures.
The alkylene oxide addition step mentioned below is carried out by using the high purity alkylcyclohexanol thus obtained to provide alkylcyclohexanol alkylene oxide adduct containing a trace amount or less of alkylphenol.
In the alkylene oxide addition step of the invention, alkylcyclohexanol obtained in the first distillation step reacts with alkylene oxide having 2 to 4 carbon atoms in the presence of an acid catalyst to give alkylcyclohexanol alkylene oxide adduct.
The alkylene oxide having 2 to 4 carbon atoms which can be used in the alkylene oxide addition step includes, for example, ethylene oxide, propylene oxide and butylene oxide. Alkylene oxide can be used singly or as a mixture. When alkylene oxide is used as a mixture, both random and block addition can be carried out. Addition mole numbers of alkylene oxide is in the range of 1 to 5 moles for 1 mole of alkylcyclohexanol.
Alkylene oxide addition mole numbers less than the range increases amount of alkylcyclohexanol which remains unreacted. On the other hand, mole numbers higher than the range increases unfavorably formation of by-products such as dioxane.
The acid catalyst used in the alkylene oxide addition step can be soluble or insoluble in the raw material alkylcyclohexanol used, and both Brxc3x8nsted acid and Lewis acid can be used for the catalyst. Specific acids include, for example, hydrochloric acid, sulfuric acid, phosphoric acid, boric acid and other mineral acids; formic acid, acetic acid, propionic acid, benzoic acid and other carboxylic acids; sulfate of aluminum, chromium, cobalt and other metals; phosphate of zirconium, iron, manganese and other metals; aluminum chloride, tin tetrachloride, antimony trichloride and other halogenides of metals; BF3, (C2H5)3OBF4, (C2H5)3OBF3 and other fluorinated boron compounds; tungstosilicic acid, tungstophosphoric acid and other hetero polyacids; aluminum oxide, SiO4-Al2O3, zinc oxide. tungsten oxide and other metal oxides; activated clay, zeolite, montmorillonite and other H-type or metal substituted type ion exchangers; and cation exchange resins having a sulfonate group, fluoroalkylsulfonate group, fluorinated alkylsulfonate group and carboxylic acid group. Preferred catalysts are aluminum chloride, tin tetrachloride, antimony trichloride and other metal halogenides, and Lewis acid base catalysts such as BF3, (C2H5)3OBF4, (C2H5)3OBF3 and other fluorinated boron compounds.
The amount of the catalyst used in the process differs depending upon the species of the catalyst and reaction temperature. The amount is usually in the range of 100 to 10,000 ppm by weight for the raw material alkylcyclohexanol. The acid catalyst soluble in the reaction mass can be removed by neutralizing with a basic compound such as alkali metal hydroxide or water-soluble amine and successively washing with water. When the salt is separated the catalyst can be completely removed by filtering off the precipitate and further washing the filtrate with water, when necessary. Further, the catalyst insoluble in the reaction mass can be usually removed by filtration. Further, the catalyst can also be separated by distillation without neutralization operation.
The reaction temperature in the first alkylene oxide addition step is usually in the range of 20 to 120xc2x0 C., preferably 30 to 70xc2x0 C. The reaction time is usually in the range of 0.1 to 30 hours, preferably 0.3 to 20 hours. The reaction pressure is usually in the range of gauge pressure 0 to 2 MPa, preferably 0.1 to 0.7 MPa. No particular restriction is imposed upon the reaction procedures. Batch procedure, semi-batch procedure and continuous procedure can be carried out. The alkylcyclohexanol alkylene-oxide adduct obtained in the step is successively used in the second distillation step below.
The object of the second distillation step of the invention is to remove unreacted alkylcyclohexanol, dioxane, aldehyde and low boiling-point by-products of the reaction and to obtain high purity alkylcyclohexanol alkylene oxide adduct. Accordingly, a distillation apparatus equipped, when necessary, with a rectifying column and reflux condenser can be used. Distillation can be carried out at atmospheric pressure or under reduced pressure. High purity alkylcyclohexanol alkylene oxide adduct can be obtained as still residue. The distillation can be carried out both by the batch procedure and continuous procedure. Recovered, unreacted alcohol can be recycled into the alkylene oxide addition step.
The alkylcyclohexanol alkylene oxide adduct obtained in the preparation processes (E) and represented by the formula (1) has a 10 ppm or less content of alkylphenol and alkylphenol alkylene oxide adduct, has a narrow addition distribution essentially consisting of adduct having alkylene oxide addition numbers of 1 to 5, is liquid, and can be used as a material of surface active agents or a raw material of alkylcyclohexanol alkylene oxide adduct having a high addition numbers of alkylene oxide.
Alkylcyclohexanol alkylene oxide adduct of the invention which is represented by the formula (1) has excellent properties as a nonionic surface active agent and can be used for a surfactant by utilizing its dominant penetrating ability, dispersing ability and emulsifying ability. The adduct can be used as an effective ingredient in many fields. Representative fields which can use the adduct include, for example, scouring cleaner, spinning agent, process oil, knitting oil, scotching oil, textile softener, dyeing auxiliaries and other uses in textile industry; deresination disperant for DP, digestion auxiliaries, pitch dispersant in paper making, antifoaming agent, deinking agent, felt cleaner, agent for coated paper and other uses in paper-pulp industry; emulsifier in emulsion polymerization, antistatic agent, antifogging agent and other uses in synthetic rubber and resin industries; emulsifier, solubilizing agent, spreading agent, hydrating agent, dispersant, lubricant and other uses in agricultural chemicals industry; metal cleaner, rust preventive and other uses in metal industry; and garment working agent, kitchen detergent, residence cleaner and other household detergents.